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-rw-r--r--pkg/cleanup/BUILD17
-rw-r--r--pkg/cleanup/cleanup.go60
-rw-r--r--pkg/cleanup/cleanup_test.go66
3 files changed, 143 insertions, 0 deletions
diff --git a/pkg/cleanup/BUILD b/pkg/cleanup/BUILD
new file mode 100644
index 000000000..5c34b9872
--- /dev/null
+++ b/pkg/cleanup/BUILD
@@ -0,0 +1,17 @@
+load("//tools:defs.bzl", "go_library", "go_test")
+
+package(licenses = ["notice"])
+
+go_library(
+ name = "cleanup",
+ srcs = ["cleanup.go"],
+ visibility = ["//:sandbox"],
+ deps = [
+ ],
+)
+
+go_test(
+ name = "cleanup_test",
+ srcs = ["cleanup_test.go"],
+ library = ":cleanup",
+)
diff --git a/pkg/cleanup/cleanup.go b/pkg/cleanup/cleanup.go
new file mode 100644
index 000000000..14a05f076
--- /dev/null
+++ b/pkg/cleanup/cleanup.go
@@ -0,0 +1,60 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package cleanup provides utilities to clean "stuff" on defers.
+package cleanup
+
+// Cleanup allows defers to be aborted when cleanup needs to happen
+// conditionally. Usage:
+// cu := cleanup.Make(func() { f.Close() })
+// defer cu.Clean() // failure before release is called will close the file.
+// ...
+// cu.Add(func() { f2.Close() }) // Adds another cleanup function
+// ...
+// cu.Release() // on success, aborts closing the file.
+// return f
+type Cleanup struct {
+ cleaners []func()
+}
+
+// Make creates a new Cleanup object.
+func Make(f func()) Cleanup {
+ return Cleanup{cleaners: []func(){f}}
+}
+
+// Add adds a new function to be called on Clean().
+func (c *Cleanup) Add(f func()) {
+ c.cleaners = append(c.cleaners, f)
+}
+
+// Clean calls all cleanup functions in reverse order.
+func (c *Cleanup) Clean() {
+ clean(c.cleaners)
+ c.cleaners = nil
+}
+
+// Release releases the cleanup from its duties, i.e. cleanup functions are not
+// called after this point. Returns a function that calls all registered
+// functions in case the caller has use for them.
+func (c *Cleanup) Release() func() {
+ old := c.cleaners
+ c.cleaners = nil
+ return func() { clean(old) }
+}
+
+func clean(cleaners []func()) {
+ for i := len(cleaners) - 1; i >= 0; i-- {
+ cleaners[i]()
+ }
+}
diff --git a/pkg/cleanup/cleanup_test.go b/pkg/cleanup/cleanup_test.go
new file mode 100644
index 000000000..ab3d9ed95
--- /dev/null
+++ b/pkg/cleanup/cleanup_test.go
@@ -0,0 +1,66 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cleanup
+
+import "testing"
+
+func testCleanupHelper(clean, cleanAdd *bool, release bool) func() {
+ cu := Make(func() {
+ *clean = true
+ })
+ cu.Add(func() {
+ *cleanAdd = true
+ })
+ defer cu.Clean()
+ if release {
+ return cu.Release()
+ }
+ return nil
+}
+
+func TestCleanup(t *testing.T) {
+ clean := false
+ cleanAdd := false
+ testCleanupHelper(&clean, &cleanAdd, false)
+ if !clean {
+ t.Fatalf("cleanup function was not called.")
+ }
+ if !cleanAdd {
+ t.Fatalf("added cleanup function was not called.")
+ }
+}
+
+func TestRelease(t *testing.T) {
+ clean := false
+ cleanAdd := false
+ cleaner := testCleanupHelper(&clean, &cleanAdd, true)
+
+ // Check that clean was not called after release.
+ if clean {
+ t.Fatalf("cleanup function was called.")
+ }
+ if cleanAdd {
+ t.Fatalf("added cleanup function was called.")
+ }
+
+ // Call the cleaner function and check that both cleanup functions are called.
+ cleaner()
+ if !clean {
+ t.Fatalf("cleanup function was not called.")
+ }
+ if !cleanAdd {
+ t.Fatalf("added cleanup function was not called.")
+ }
+}